Sulfonated polystyrene nonwoven

Abstract

Sulfonated polystyrene fibers having an average diameter from 450 nm to 2000 nm and a capacity from 0.05 meq/g to 2.0 meq/g.

1 . A sulfonated polystyrene nonwoven comprising fibers with an average diameter from 450 nm to 2000 nm and a capacity from 0.05 meq/g to 2.0 meq/g. 
     
     
         2 . The nonwoven of  claim 1  having a capacity from 0.4 to 1.5 meq/g. 
     
     
         3 . The nonwoven of  claim 2  in which the fibers have an average diameter from 450 nm to 1750 nm. 
     
     
         4 . The nonwoven of  claim 3  in which at least 90 wt % of the polystyrene molecules contain crosslinks. 
     
     
         5 . A method for producing a sulfonated polystyrene nonwoven; said method comprising steps of:
 a) providing polystyrene nonwoven fibers having an average diameter from 450 nm to 2000 nm;   b) contacting the polystyrene fibers with a crosslinking agent at a temperature from 30° C. to 150° C.; and   c) contacting a product of step b) with at least 90 wt % sulfuric acid at a temperature from 30° C. to 150° C.   
     
     
         6 . The method of  claim 5  in which the fibers have an average diameter from 450 nm to 1750 nm. 
     
     
         7 . The method of  claim 6  in which step c) is carried out for a time sufficient to produce sulfonated polystyrene fibers having a capacity from 0.4 meq/g to 2.0 meq/g. 
     
     
         8 . The method of  claim 7  in which the crosslinking agent is sulfuric acid and an aldehyde or dialdehyde and in which step b) is carried out for a time sufficient to produce sulfonated polystyrene fibers, wherein at least 90 wt % of the fibers contain crosslinks. 
     
     
         9 . The method of  claim 8  in which step c) is carried out for a time sufficient to produce sulfonated polystyrene fibers having a capacity from 0.4 meq/g to 1.5 meq/g. 
     
     
         10 . A method for removing metals from a liquid; said method comprising contacting said liquid with a polystyrene nonwoven comprising fibers with an average diameter from 450 nm to 2000 nm and a capacity from 0.05 meq/g to 2.0 meq/g.